In general, a DM technique is a technique for changing setting of a device (a DM client) by remotely controlling a variable or an object stored in the device by a server (DM server). Commonly, when a particular command is received from the DM server, the DM client immediately performs the corresponding command.
The DM server performs DM such as reading, changing, deleting and generating a value of a particular management object through a process in which the DM client performs the command upon receiving it.
The DM technique is a standard for supporting various functions compared with any other management technique, including a DM protocol specification, a specification relating to a way how to express a DM document, a specification relating to a way how to bind between transmission protocols, a specification relating to a DM tree and a DM node, a specification relating to a DDF (Device Description Framework), and a specification regarding notification, etc.
The DM technique is implemented such that the DM server transmits the command relating to the particular management object existing within the device and then the DM client performs the corresponding command upon receiving it. In this case, the DM object mainly exists in a database of the device and is logically connected with a node of the DM tree existing within the device. Namely, the DM server can issue a management command by accessing a node logically connected with the management object through a URI (Uniform Resource Indicator).
Thus, in order for the DM server to access resources or the object present in the DM client, each resource or object has a node. The nodes are associated with resources or objects, the DM server can access a corresponding node and manage the corresponding resource or object. In this case, in order for the DM server to manage the resources or objects associated with each node, each node has attribute values indicating information regarding the resources or objects to which it belongs.
FIG. 1 illustrates the attributes of nodes of the DM client. The resources stored in the DM client can be divided into resource 1, resource 2, etc. according to characteristics of each resource, and each node is associated with a node. A node x has fields indicating information on the resource 1 and a node y has fields indicating information on the resource 2. All the nodes of the DM client including the node x and node y have the following fields:                ACCESS CONTROL LIST: a list of external devices that can access corresponding resources        FORMAT: an encoding type of a corresponding resource        NAME: a name of a node        SIZE: a size of a corresponding resource        TIME STAMP: time point at which a value of a corresponding resource was finally changed        TYPE: a form or type of a corresponding resource        
The fields are applied to all types of nodes in the same manner regardless of nodes.
Namely, all the nodes have the set of same fields including ACCESS CONTROL LIST, FORMAT, NAME, SIZE, TIME STAMP and TYPE.